Positron emission tomography (PET) is an imaging method that uses positron emitting radiotracers to track the biochemical, molecular, and/or pathophysiological processes in humans and animals. In PET systems, positron-emitting isotopes serve as beacons for identifying the exact location of diseases and pathological processes under study without surgical exploration of the human body. With these non-invasive imaging methods, the diagnosis of diseases may be more comfortable for patients, as opposed to the more traditional and invasive approaches, such as exploratory surgeries.
One such exemplary radiopharmaceutical agent group includes gallium-68 (Ga-68), which may be obtained from the radioisotope germanium-68 (Ge-68). Germanium-68 has a half-life of about 271 days, decays by electron capture to Ga-68, and lacks any significant photon emissions. Gallium-68 decays by positron emission. These properties make gallium-68 an ideal radioisotope for calibration and transmission sources. Thus, the availability of the long-lived parent, germanium-68, is of significant interest because of its generation of the shorter-lived gallium radioisotope.
Germanium-68 may be obtained by irradiating a target body containing gallium to cause gallium-69 within the target body to transmute to germanium-68 by the (p, −2n) reaction. Germanium is conventionally stripped from the target body by contacting the target body by an acidic mixture comprising hydrochloric acid. Germanium may be extracted from the stripped solution by use of non-polar solvents and hydrochloric acid.
Use of halides during stripping and extraction of germanium-68 allows volatile germanium halide compounds (e.g., GeCl4) to form. Such volatile germanium-68 compounds may evaporate from the liquid phase causing yield loss and contamination.
A need exists for processes for stripping and extracting germanium-68 with high yield and with reduced formation of volatile germanium halide compounds.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.